Calculating device



Jan. 17, 1939. F. w. LUDECKE ET AL 2,143,892

CALCULATING DEVICE Filed Sept. 25, 1937 Patented Jan. 17, 1939 7 'umTsos'rATss. PATENT OFFICE- CALOUIATINGDEVICE Fred W. Lndeoke, Berkeley, and 0. Victor Smith,

Oakland, Calif. 4

Application September as, 193 1, Serial no. 105,111: 11 Claims. (01. ass-sol .This invention, a calculating device, is an improvement over the conventional slide rule, over which it diners in being constructed with a stationary cursor and movable body and slide,

quired in the calculations, and the body may be a single ribbon or divided into two ribbons, and the same also applies to the slide. Twoor more ribbons can be employed or incorporated in the device, according to the type of calculations which are to be solved.

The usual types of slide rules are substantially limited to a length of about ten inches for conreceptacle underneath the exposed portion, or

may have their opposite ends deposited'in a suitable receptacle or wound on reels.

As will be readily understood, if ribbons having scales 100 inches long are employed, there canbetentimesasmanydivisionsasinaten inch slide rule, and the accuracy will thus be multiplied ten-fold. The scales obviously are not limited to a length of 100 inches, but may be of any length.

The objects and advantages of the invention are-as follows:

First, to provide scales in a slide rule which may be formed to any desired included length, whereby the degree of accuracy in calculations may be increased to any desired value over those obtainable with existing types of slide rules.

Second, to form the scales on flexible ribbons which may be gathered in a suitable receptacle or wound on reels.

Third, to,'provide means for rapidly or slowly propelling saidribbons, either separately or collectively, at will.

Fourth, to provide means for indicating the I relative position of the various indices or divisions of the scales to the hair line on the cursor as the ribbons are propelled either rapidly or this specification, and in which similar reference characters are used to designate similar parts throughout the several views, of which;

Fig. 1 is a plan view of the invention, with portions broken away to show the clutch mechanism for simultaneous driving of the ribbons, and the spools, and also with the gear covers removed to .show the gear arrangements.

Fig. 2 is a sectional elevation taken on a line 2-2 of Fig. 1, with the exception that a portion of the side wall of the housing is retained to show the brake mechanism, and a portion of one pinion is broken away to show the sprocket teeth on the spools.

Fig. 3 is a fragmentary sectional end elevation taken on a line 3-3 of Fig. 2.

Fig. 4 is a diagrammatic view of the high speed and low speed scale position indicators on the ribbons and cursor.

The conventional slide rule consists of a body and slide of rigid material which are relatively movable, and a cursor which is slidable over the length of the body, and having a hair line for registration with the respective scales formed on the body and slide. 4

In this invention, the slide and the body are made of flexible ribbons, which may be continuous, or which may have their ends gathered in a suitable receptacle or wound on reels, and these ribbons may be independently adjusted, or they respectively a body unit and a slide unit, which are structurally identical but oppositely disposed,

and mounted in parallel-relation as shown in Fig. 1, although the device may have a plurality.

of units or ribbons, and still fall within the scope oi this invention.

The slide consists of one of the ribbons, as N, and the body consists of another ribbon, as H, and the cursor consists of the transparent cover I! which is provided with a hair line I, the body ribbon being supplied with the usual scales provided on the body of the conventional slide rule, and the slide ribbon being provided with the usual scales provided on the slide of the conventional slide rule, except that the scales are divided into a greater number of parts and the scales are of much greater length.

Each ribbon, Iii, I i, is operated over two spaced apart spools, as H. II for scale or ribbon II, and It, II for ribbon II, and these spools are allot the same diameter and are provided with sprocket teeth It for cooperation with the perforations it formed in the respective ribbons.

The respective pairs of spaced apart spools are geared together for synchronous rotation, as by means of pinions 2t and 2| and gear :2, (gear 2i being partly broken away to show the spool and sprocket structure), and functioning to keep the exposed portions of the ribbons taut between the spaced apart spools, and also functioning as through the medium of which the spools may be independently rotated in either direction at y will The spools at the other end, as it and it are mounted and equipped for either independent or simultaneous rotation, the general structure being identical to the structure of spools it and all except for the clutch for locking the two spools together for rotation as a unit.

With this arrangement, it is of utmost importancethat the spools be locked together in any relation, therefore a friction type clutch is shown as illustrative of one means of attaining this result.

In both sets of coaxial spools, one spool is fixedly mounted on a shaft 26, with the other spool mounted on a quill shaft 2?, spool ill being fixed against rotation and sliding on its quill shaft, while the quill shaft is slidable but nonrotatable in the spool i6, and the ends of shafts 26 are in both instances rotatable in their associated quill shafts.

The quill shafts 27 have amxed at their outer ends the knurled knobs 25 and. 28, and shafts 26 are provided with the knurled knobs 2d and 29.

The shafts 26 and 21 are rotatable in the bearings 30 and 3! respectively, and which are integral with, or mounted on the housing side walls 32 and 33 respectively.

. The clutch consists of a plurality of bowed spring fingers or shoes, as 34 and 35, which are fixed to the spool l6 and tend to normally clear the inner periphery of spool M as shown. A disc 36 is fixed to the inner end of the shaft 27 for spool 16, and which upon retractioniby means of knob 28 as indicated by the dotted' lines at 28', causes the disc to urge the fingers outwardly to grip the spool 14 to cause it to turn with the spool I 8 in adjusted registry.

when the clutch is engaged, both ribbons l0 and II are driven as a unit at the same speed and adjusted together relative to the hairline IS. The clutch is instantly releasable at will by pressing the knob back to the position shown The reels and compensating means therefor are identical, and each reel, as shown inFlg. 3, consists of a hub 31.pro'v*ided with a flange at each end, respectively 38 and 39, the hubs all being of the same diameter and mounted on the respective shafts 40 and 4| von which they are freely rotatable.

The ends of the shafts 40 and, are mounted -ets and associated devices.

The means compensating for variationsin cumulative diameters of the ribbon reels consists of two sets of auxiliary reels and a tape for each set, and each set consists of two spaced apart compensating reels, each having a hub 42 of the same diameter as the hubs 31 and coaxial therewith, and having aflange 43, with theflange 39 functioning as the other aligning member for .-has its opposite ends attached to the respective hubs of the spaced apart reels,

The ribbons ill, ii, and tapes 44 are of the same thickness but may be of diflerent material,

tapes 46 being preferably formed of a flexible material having friction surfaces which may be produced by oxidation or mechanical means, but

' should consist of material having a very low 3t and associated hub 42 are identical as shown in Fig. 3.

The compensating driving means between the tape reels consists of a belt 31 for each'tape, and preferably of a half round form as shown in section in Fig. 3, with the flat side cooperating with Y the tape at and encompassing the spaced apart cumulative reels, and lying on the intervening section of tape between the reels. A grooved idler pulley 48 cooperates with the portion of the belt 47 extending between the spaced apart reels, and belt tensioning means consists of a lever 59 having an idler shaft 50 fixed intermediate its ends to support the idler 48, one end of the lever 49 being pivoted at'il, and'a tension spring cooperates between the other end of the lever and the bottom 53 of the housing, as shown Since the belt fl'operates over the accumula- 4 tion of tape on the reels, and the accumulated diameters of ribbon reels and tape reels are always identical, perfect compensation and uniform speed of both ends of the'ribbon alone can result.

When the ribbon is driven by the low ratio' drivingmeans, as by means of knobs 24, 25, 28,

29 and their associated sprockets, the same re-' sults. as to synchronism and compensation are attained as when operated by the high ratio driving means through the knobs 54 and associated gears and pinions, as the tapes, ribbons, belts and reels all cooperate to maintain a uniform tension on the exposed portions of the ribbon.

For the purpose of maintaining uniform tension on the ribbons, the bearings at the re-. spective ends of shaft 4| are diagonally slidable in the slot SS'and are retracted by means of springs 56 coupled between the bearings and the bottom of the housing.

. Means for retaining the ribbons individually at desired scale settings consists of a brake shoe for each gear 22, indicated at 51, which shoe is pivoted at 58 to the housing side wall, 32, I3, and urged to cooperate with the inside surface I! of controlled by a lever 6|, providing for accurate setting of either ribbon with any division or point between divisions to the hair line. ll. i

The high speed position indicating means for indicating the relative location of the indices of the gear flange by means of a cam 60 which is the scales consists of a straight line 62 of some distinguishing color or character extending diagonally from one end 63 ot the set of scales on i the ribbon to the diagonally opposite end 84, and

, a plurality of transverse scales 5 and 06, (which may be formed diagonally if desired), formed in the cursor or transparent top II of the d vice, whereby, as the ribbon is driven at high speed it is merely necessary to watch the transverse travel of the line 82 relative to the scales '5, 66 until it falls between the two numbers which include the value desired.

As shown in Fig. 1, the line 62 falls between 4 and on scale 65, and the ribbon has reached the position for slow speed adjustment to any value between 4 and 5.

Since the distance between 1 and 2 for instance, in a logarithmic scale 100 inches long is about inches, and in longer scales would be correspondingly longer, it is advisable to provide additionally,. low speed position locating means, therefore, additional lines, straight or curved, as may be required, are formed between diagonal points on each scale section, such as line 81 extending from 63 to 68, corresponding to 1 to 2 on the scale and forming one scale section,

another line 69- extending' from III to H diagonally across another scale section 2 to 3, and so on for-each unit scale section of the scale.

As indicated in Fig. 1, line 62 on ribbon ii registers between 2 and 3 on the transverse scale 12, while line 89 lies between 3 and 4. For line 62 the scale is read for the first significant figure. while line is used for the second significant figure, and for further significant figures the reading is attained through the medium of the hair line, or may be obtained through the medium of additional locating lines adapted to divisions of the unit scales. The reading indicated would be 2 for the first significant figure, and about .38 for the second and third significant figures. The ribbon is now adjusted until the exact value, say 2.383 registers with the hair line i3, being the final adjustment.

In operation it is merely necessary to register the required values on the ribbons with the hair lineit, and when required in calculations, in-

stead of moving the cursor as on the conventional slide rule, after suitable correlation of the body and slide scales to the hair line, the knob 28 is pulled out to the position 28' which forces the shoes 34, 35, to clutch the spool i4, after which the ribbons are adjusted as a unit to the next selected value by means of either high ratio or low ratio driving. By pressing the knob 28 back to the full line position, the clutch is released for individual adjustment of the respective scales.

It will be understood that the reeling means shown in Fig. 3 may be dispensed with and continuous ribbons in the form of a belt may be employed, permitting the unexposed portions of spirit or scope of the invention or sacrificing any of the advantages thereof.

We claim: 1. A; calculating device comprising two ribbons each having sprocket-tooth-receiving perforations iormed throughout its length; two parallel spaced-apart shafts rotatably mounted; a

spool fixed on each shaft and a spool freely rotatable on each shaft; sprocket teeth formed on each spool; a knob associated with each spool for independent rotation thereof; a clutch associated with one spool and cooperatively related to the other spoolon the same shaft and means associated with one of said knobs and operatively connected to said clutch for selectively clutcl ing and declutching the other spool at will through axial movement of said one of said knobs; positive actingmutual driving means cooperating between the respective spools on the respective shafts for maintaining the respective i iptroclrets in predetermined ribbon-tightening rea ion.

2. A calculating device comprising two parallel ribbons each having sprocket-tooth-receiving perforations formed throughout their lengths; two sets of spaced apart spools, one set for each ribbon forming two pairs of coaxial spools: sprocket teeth formed. on each spool; positive-acting mutual driving means cooperating between each of said two sets of spaced-apart spools maintaining the angular relation of the sprockets to keep the intervening portions of the ribbons taut through cooperation of predetermlnedly related sprocket teeth with the perforations; a clutch associated with one pair of said spools; a driving knob associated with each spool of one pair,

one of said driving knobs having an operative connection with said clutch for clutching and de-clutching said one pair of spools at will by axial movement of said one of said driving knobs.

3. A structure as claimed in claim 2; a ribbon reel for each end of each ribbon and a coaxial compensating reel fixedly associated with each ribbon reel forming two sets of spaced-apart compensating reels; and compensating, mutually acting takeup means cooperating between the spaced apart compensating reels; said mutually acting takeup means being independently actuated through the'movement of the associated ribbon and being free of any directional urging effect on said ribbons and being controlled entirely by the urgence of said ribbons and forming auxiliary means for maintaining the intervening portions of said ribbons taut.

4. A structure as claimed in claim 2; a ribbon reel for each end of each ribbon and a coaxial compensating reel fixedly associated with each ribbon reel forming two sets of spaced-apart compensating reels; and compensating, mutually acting takeup means cooperating between the spaced apart compensating reels; said mutually acting takeup means being independently actuated through the movement of the associated ribbon and being free of any directional urging effect on said ribbons and being controlled entireiy by the urgence of said ribbons and forming auxiliary means maintaining the intervening portions of said ribbons taut, said compensating mutually acting takeup means comprising cumulative means winding from one compensating reel to the other of each set, and mutual driving means associated with said cumulative means accumulated on said compensating reels.

5. A structure as claimed in claim 2, and compensatlng, mutually acting takeup means comprising a coaxial compensating reel attached to each ribbon forming two sets of compensating reels; cumulative means windabie from one compensating reel to the other of each set, and mutual driving means associated with the cumulative means' equalizing opposed tension on the intervening portions of the ribbons and being free of urging influence on the ribbons toward driving the ribbons in either direction.

6. A structure as claimed in claim 2, a coaxial compensating reel fixedly associated with each ribbon reel forming two sets of spaced apart compensating reels; 3, compensating ribbon windable from one compensating reel to the other of each set and having cumulative diameters on the compensating reels equal to the cumulative diameters of the ribbons on the associated ribbon reels; and, a belt operating over the cumulative diameters of the compensating reels of each set, forming mutual driving means between the compensating reels -of each set subjecting the ribbons to equalized tension at opposite ends and being free of directional driving urgence on the ribbons.

Z. A structure as claimed in claim 2, a coaxial compensating reel fixedly associated with each ribbon reel forming 7 two sets of spaced apart compensating reels; a compensating ribbon windable from one compensating reel to the otherlof each set and having cumulative diameters on the compensating reels equal to the cumulative diameters of the ribbons on the associated ribbon reels; and, abelt operating over the cumulative diameters of the compensating reels of each set, forming mutual driving means between the compensating reels of each set sub- Jecting the ribbons to equalized tension at opposite ends and being free of-dlrectionai driving urgence on the ribbons, and means increas ing the wrap of said belts on the cumulative peripheries of said compensating reels andcoincidently maintaining uniform tension and taking up stretch of the belts.-

' 8. A structure as claimed in claim 2, a coam'al compensating reel fixedly associated with each .ribb'on reel forming two sets of spaced apart compensating reels; a compensating ribbon windable from one compensating reel to the other of each set and havingcumulative diameters on the compensating reels equal to the cumulative diameters of the ribbons on the associated ribbons reels; .a belt operating over the cumulative diameters of the compensating reels. of each-set subjecting the ribbons to equalized tension at their opposite ends and forming mu:- tual driving-means free from directional driving urgence on the ribbons; said belts having a plane inner face for full coperation with said compensating ribbons, and an outer face convex in cross-section; a grooved pulley cooperating with said outer face and intermedlately located relative to the compensating reels of each set to ma ntain alignment of the belts with the compensating ribbons, to increase the wrap of the belts on the cumulative peripheries, and to maintain predetermined tension on the belts.

9. A calculating device comprising two sets of spaced apart ribbon sprockets,- the respective sprockets. of the'respectivesets being coaxially mounted forming two pairs of coaxial sprockets;

a knurled. knob associated with eachsprocket of at leastone pair for manual rotation thereof at will; a clutch associated with one sprocket and 1 cooperatively related to the other coaxial sprocket; means associated with the knurled knob of one of said last named sprockets and cooperat-' ing with said clutch and engaging'and disengaging said clutch with said other sprocket through axial movement of the said knurled knob: a pinion fixedly associated with each sprocket of both sets forming two sets of pinlons'; a gear for each set of pinions and coincidently meshing with both pinions, thereof for maintaining the predetermined relation between the teeth of the knobs.

10. A structure as claimed in claim 9; a ribbon reel for each end of each scale ribbon; a compensating reel fixedly associated with each ribbon reel and being of the same initial diameter,

, forming two sets of spaced apart compensating reels; a compensating ribbon coincidently taken up on one compensating reel and paid out on the other of each set and having under all conditions of takeup and payout a cumulative diameter exactly equal to the cumulative diameter of the scale ribbon on its associated ribbon reel; and a belt for each set ,of compensating reels and opcrating over and about the accumulations of compensatingribbon on' the respective compensatng reels of each set,.forming in combination,

auxiliary tensioning means for the intervening portions of the respective scale ribbons and mu tual driving means free of directional urgence on the scale ribbons.

.11. A calculating device comprising two cpax'al units in parallel, each unit comprising a set of two spaced apart sprockets, two spaced apart scale ribbon reels and a compensating reel of equal diameter coaxial with and fixed to each scaleribbon reel; a scale ribbon having its respective ends attached to the respective scale ,ribbon reels and operating over said sprockets and having perforations for receiving the teeth of the sprockets; an axially-movable knob for manual rotation of one sprocket; a clutch for said one sprocket and cooperatively related to the coaxial sprocketfor the other unit; means oooperatively associated with said clutch and said oneknob engaging and disengaging said clutch with respective opposed axial movements '0! said one knob; positive-acting, relation-maintaining means for said sprockets maintaining the intervening portion of said scale ribbon taut; a com-. pensating' ribbon having its ends attached to the respective compensating ribbon reels and having a thickness equal to the thickness of said scale ribbon and having its respective top and bottom surfaces frictionally formed and having a cumu-- lative diameter on each compensating reel equal to the accumulated diameter of scale ribbon on its associated-scale ribbon reel; and mutual driving means comprising a belt operating over the accumulations of compensating ribbon on the respective compensating reels; wrap increasing and tensioning means for said belt; and tensioning means urging retraction of one compensating reel and its associated scale ribbon reel, providing predetermined tension on both ends of the intervening portion of said scale ribbon through coincident transference of the urgence through one end of the interveningportion of said scale ribbon, and in opposition through said belt to the other end of the intervening portion of said scale ribbon, whereby the tension on the scale ribbon is equalized; said mutual driving means being free of directional. urgence on said scale ribbon and FRED W. LUDECKE. C. VICTOR slum. 

